• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.171-177
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• 2005

Nutritional compositions and antioxidative activity of Kabocha squash (Cucurvita maxima Duch) as health food were compared with those of pumpkin (Cucurvita moschata Duch). Kabocha squash had higher soluble solids and twofold harder flesh than pumpkin. Crude protein, crude lipid and total amino acid contents of Kabocha squash were higher than those of pumpkin. Major free sugar in Kabocha squash was sucrose, and its content were 2.1 times higher than that of pumpkin. Major organic acids of Kabocha squash and pumpkin were succinic and malic acid, respectively. Kabocha squash had higher amounts of vitamins $A,\;B_1,\;B_2,\;C$ and C than pumpkin, while both showed similar mineral contents except for iron. Contents of Total pectin and hydrochloric acid soluble pectin of Kabocha squash were 17.00 and 7.37 g/100 g AIS, respectively. In pumpkin, total pectin content was 25.14 g/100 g AIS, and water soluble pectin content was higher than those of other pectin fractions. Contents of carotenoid in Kabocha squash and pumpkin were 285.91 and 24,62 mg% d.b., respectively. Kabocha squash had higher electron-donating radical-scavenging activity, SOD-like activity and nitrite-scavenging effect than pumpkin.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.188-193
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• 1988

The objective of this study was to investigate the technical feasibility of producing toxicant-free rapeseed by germination. To this end, rapeseed (Brassica napus L.) was germinated at $25^{\circ}C$ for 120 hours, and the compositional changes of fatty acids and minerals were determined in every 24 hours during germination. Repeseed slightly decreased it's fat content during germination, whereas it showed a tendency to increase protein content. The contents of oleic, erucic, linoleic, linolenic, stearic, palmitic and arachidic acids in rapeseed before germination were found to be 24.6, 15.5, 10.6, 9.5, 1.0, 2.4 and 5.3% respectively. They were gradually decreased until 96 hours and showed a slight increase in 120 hours during germination. However, there was no significant difference in the variation of fatty acids composition in rapeseed during gemination. The content of minerals-phosphorous, calcium, magnesium, zinc, manganese, copper and iron-in rapeseed before germination were 6367, 3068, 2667, 80.3, 26.5, 15.9, and 94.4 ppm respectively and sodium was detected in trace. The mineral contents in rapeseed were gradually decreased in the early period of germination, but showed a slight increase in 120 hours.

• Economic and Environmental Geology
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• v.34 no.2
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• pp.157-166
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• 2001

Numerous base-metal bearing hydrothermal quartz vein deposits occur in the Hunan province of southern China. The Tangguanpu lead-zinc-tin-silver mine is the major producer among these deposits. Lead-zinc-tin-silver mineralization occurs in a single stage of massive quartz veins which filled fractures in fault zones within Paleozoic metasedimentary rocks. Sphalerite, chalcopyrite, galena, pyrite, arsenopyrite and pyrrhotite are the principal sulphide minerals in the Tangguanpu lead-zinc ores with minor amounts of tin- and antimony-bearing sulphides (stannite, teallite, boulangerite and tetrahedrite). Based on the iron and zinc partitioning between coexisting stannite and sphalerite, the formation temperature for this mineral assemblage range from 300$^{\circ}$ to 330$^{\circ}$C, which relatively agree with the upper part of homogenization temperature of fluid inclusion in quartz (20T-358$^{\circ}$C). Fluid inclusion data show that main lead-zine-tin-silver mineralization occurred from $H_{2}O$-NaCl fluids with relatively low salinities (11.2-7.3 wl.% eg. NaCI) at temperatures between 207$^{\circ}$ and 358$^{\circ}$C. The relationship between homogenization temperature and salinity suggests a history of cooling and dilution followed by initial boiling. Evidence of initial fluid boiling may indicate the fluid trapping pressures of 180 bars. The ${\delta}^{34}S{{\Sigma}S}$ values of -5.0 to 1.1 %, indicate an igneous source of sulfur in the Tangguanpu lead-zinc-tin-silver hydrothermal fluids.

• Journal of the Mineralogical Society of Korea
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• v.19 no.1 s.47
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• pp.49-61
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• 2006

This study was undertaken to investigate the origin of suspended matter to induce turbidity water in Gachang dam in view of environmental geology. During the period from May to August 2004, field works and sampling were carried out three times at the dam and along its streams, and chemical and mineralogical analyses such as ICP, IC, particle size analyzer, XRD and SEM were made on water, soil and suspended matter in water. Electrical conductivity (EC), turbidity, the contents of cation and anion increase from upstream toward the dam mostly due to the geological factors such as weathring of the rocks causing the increase of the total ion content. Vermiculite, illite, kaolinite, quartz, feldspar and iron hydroxide are commonly found in suspended matters in water and soils. Finer particles (d10) in soil increase slightly toward downstream and the vermiculite content is highest in the dam water. Since geological differences are not significant, mineralogy are similar in suspended matters and soils. Clay mineral compositions present in suspended matters were alsmost the same as those in soils, indicating the origin of soils by weathering of host rocks and being transported to the dam by stream water.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.92-111
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• 2011

This study focus on the restoration stone selection of break-out part based on material characteristics analysis and the conservational safety diagnosis using various nondestructive techniques for Jungdong and Banjukdong Stone Auariums. As a result, the original rocks of the stone aquariums body are porphyritic granodiorite with magnetite-series having igneous lineation, microcline phenocryst, veinlet and basic xenolith. As a result of the provenance presumption of the host rock, a rock around Gamgokri area in Nonsan City was identified the genetically same rock. Therefore, the rock is appropriate for restoration materials of the break-out part. The deterioration assessment showed that the stone aquariums were highly serious scaling, scale off and blackening. Particularly, the front face of Banjukdong stone aquarium needs reinforcement of structural crack (760mm) caused from igneous lineation of biotite. Blackening contaminants on the stone aquariums surface occurred by combining iron oxide, manganese oxide and clay mineral. Also, major factors of efflorescence contaminants were identified as calcite (Jungdong stone aquariums) and gypsum (Banjukdong stone aquariums). The physical characteristics of stone aquariums appeared that the original and new stone is third (moderately weathered) and second grade (slightly weathered), respectively. This study sets up an integrated conservation system from material analysis to restoration stone selection and conservational safety diagnosis of Jungdong and Banjukdong stone aquariums.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.244-250
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• 2020

β-Tricalcium phosphate (β-TCP, Ca3(PO4)2) is a kind of biodegradable calcium phosphate ceramics with chemical and mineral compositions similar to those of bone. It is a potential candidate for bone repair surgery. To improve the bioactivity and osteoinductivity of β-TCP, various ions doped calcium phosphate have been studied. Among them, Iron is a trace element and its deficiency in the human body causes various problems. In this study, we investigated the effect of Fe ions on the structural variation, degradation behavior of β-TCP. Fe-doped β-TCP powders were synthesized by the coprecipitation method, and the heat treatment temperature was set at 925 and 1100℃. The structural analysis was carried out by Rietveld refinement using the X-ray diffraction results. Fe ions existed in a different state (Fe2+ or Fe3+) with different heat treatment temperatures, and the substitution sites (Ca-(4) and Ca-(5)) also changed with temperature. The degradation rate was fastest at Fe-doped β-TCP with heated at 1100℃. The cell viability behavior was also enhanced with the substitution of Fe ions. Therefore, the substitution of Fe ion has accelerated the degradation of β-TCP and improved the biocompatibility. It could be more utilized in biomedical devices.

• Resources Recycling
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• v.31 no.4
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• pp.12-18
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• 2022

Korea depends on the import of raw materials such as iron ore and coal for the steel industry. These raw materials have a major impact on the cost, productivity, and quality competitiveness in the global steel industry. To secure the competitiveness of steel companies, it is necessary to reduce the country's dependence on raw materials. This can be achieved using byproducts with a high Fe content, which are primarily generated by the steel industry. These byproducts are available in the form of a very fine powder, which can disperse as dust when used directly in plant processes. Dust dispersion has a negative impact on the environment and can lead to the loss of raw materials. To enable the use of a wide range of Fe-containing byproducts, it is necessary to pretreat them in the form of larger aggregates such as pellets and briquettes. There are several methods to achieve such aggregates. There are two ways to produce briquettes: using a hot briquette, which supplies additional heat to produce briquettes, or using a cold briquette, which does not use heat. A method for producing cold briquettes using Fe-containing byproducts was investigated in this study. The yield ratio and briquette strength were examined under various manufacturing conditions.

• Journal of Conservation Science
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• v.37 no.2
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• pp.77-89
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• 2021

In this study, materials and color formation techniques were assessed for black potteries excavated from the Janghyeon-dong, Jungsan-dong and Gyodong-ri sites during the Proto-Three Kingdoms period in Ulsan, Korea. Although the black potteries were black superficially, the inner cores were either black or reddish yellow. Microscopy analysis identified that body clay was used for reddish iron oxide rich soils with quartz, alkali feldspar and mica, along with grains of myrmechite texture. Additionally, as marginal differences exist in the contents of SiO₂, Fe₂O₃ and CaO, the composition of the host rock and clay distributed around the sites was affected. Thus, we can deduce that pottery was made by soiling at a short distance. Raman spectroscopy results revealed that the black layer of the black pottery was used as amorphous combustion carbon. In addition, as a transparent layer of brown lacquer was observed on the substrate that was in contact with the surface layer, the black layer of the pottery induced black color development by a combination of combustion carbon and lacquer. Based on the mineral composition and microtexture of the body clay, the firing temperature of the potteries seemed to range from 750 to 850℃, whereas the lacquer layer was pyrolyzed at 468℃ by thermal analysis. Therefore, a combined layer of combustion carbon and lacquer, which formed the black color, was painted after the body clay was fired.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.781-789
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• 2023

We investigated the sensory and quality characteristics of gambas al ajillo retort foods with nondigestible maltodextrin (trial gambas) compared with commercially available frozen gambas al ajillo (control). Trial gambas demonstrated approximate compositions of 75.8% moisture, 11.3% protein, 5.8% lipid, 1.7% ash, and 5.4% carbohydrates, indicating lower lipid and carbohydrate contents but higher moisture, protein, and ash levels than that of the control. Sensory assessments conclusively established the superior overall acceptability of trial gambas over the control. Trial gambas exhibited a total amino acid content of 9.62 g/ 100 g, surpassing the 5.39 g of the control. The major amino acids, such as lysine, leucine, arginine, aspartic acid, and glutamic acid, contributed significantly to its enhanced nutritional profile. Mineral analysis revealed higher calcium, phosphorus, magnesium, and iron levels in trial gambas and lower potassium levels than that in the control. Fatty acid profiling identified 18:1n-9 (67.8%) and 16:0 (11.9%) as the predominant fatty acids, in concordance with the control. This study substantiates trial gambas with the health-oriented preferences of the MZ generation while presenting superior sensory and quality attributes compared with the control.

• Clean Technology
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• v.30 no.2
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• pp.105-112
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• 2024

Globally, the demand for electric vehicles has surged due to greenhouse gas regulations related to climate change, leading to an increase in the production of used batteries as a consequence of the battery life issue. This study aims to selectively leach and recover valuable metal lithium from the cathode material of spent LFP (LiFePO₄) batteries among lithium-ion batteries. Generally, the use of inorganic acids results in the emission of toxic gases or the generation of large quantities of wastewater, causing environmental issues. To address this, research is being conducted to leach lithium using organic acids and other leaching agents. In this study, selective leaching was performed using the organic acid methane sulfonic acid (MSA, CH₃SO₃H). Experiments were conducted to determine the optimal conditions for selectively leaching lithium by varying the MSA concentration, pulp density, and hydrogen peroxide dosage. The results of this study showed that lithium was leached at approximately 100%, while iron and phosphorus components were leached at about 1%, verifying the leaching efficiency and the leaching rates of the main components under different variables.